活性焦和活性炭负载纳米铁处理TNT红水中的二硝基甲苯磺酸钠

Treatment of dinitrotoluene sulfonates in TNT red water by active carbon supported and active coke supported NZVI

以活性焦和活性炭为载体,采用液相还原法制备了负载纳米铁,比较了两种负载纳米铁对TNT红水中难降解物质二硝基甲苯磺酸钠(包括2,4-DNT-3-SO3Na和2,4-DNT-5-SO3Na)的去除能力。实验结果表明,作为负载材料活性焦的相对有效比表面积与孔体积要优于活性炭,而且有利于更好地发挥出负载纳米铁的优势。单位面积活性焦负载纳米铁去除2,4-DNT-5-SO3Na的能力明显高于活性炭负载纳米铁,单位面积活性焦负载纳米铁去除2,4-DNT-3-SO3Na的能力在较小投加量条件下高于活性炭负载纳米铁,但均随投加量的增加而下降;而对于活性炭负载纳米铁,其单位面积去除能力基本不受投加量的影响,而且对二硝基甲苯磺酸钠的去除率高于活性焦负载纳米铁。耦合混凝沉淀的总去除效果表明,单位面活性焦负载纳米铁对2,4-DNT-5-SO3Na的去除能力高于活性炭负载纳米铁,而对2,4-DNT-3-SO3Na的去除能力则低于活性炭负载纳米铁。

Activated carbon supported nanoscale zero-valent iron（NZVI/AC） and activated coke supported nanoscale zero-valent iron（NZVI/ACoke） were prepared using liquid phase reducing method.Their transformation capacities of 2,4-DNT-3-SO3Na and 2,4-DNT-5-SO3Na,a kind of degradation refractory nitro aromatic compounds,were compared.The experimental results revealed that activated coke was a better choose for supporting NZVI than activated carbon for the larger relative effective surface area and pore volume as well as enhancing the synergistic action between NZVI and carrier.NZVI/ACoke showed a higher transformation capacity of 2,4-dinitrotoluene sulfonates per unit area than NZVI/AC at first,but it decreased as the amount of NZVI/ACoke increased.However,the area-modified transformation capacities of NZVI/AC almost did not change with increasing amounts of NZVI/AC,and the removal efficiencies of 2,4-dinitrotoluene sulfonates were higher than those gained by NZVI/ACoke.When combined with coagulation-sedimentation,NZVI/ACoke showed a higher transformation capacity of 2,4-DNT-5-SO3Na per unit area than NZVI/AC,but a lower transformation capacity of 2,4-DNT-3-SO3Na than NZVI/AC.